From: Amara Graps (amara@amara.com)
Date: Fri Jan 04 2002 - 14:36:10 MST
----------------------------------------
URL for Abstracts http://xxx.lanl.gov/abs/
Mirror at http://xxx.uni-augsburg.de/abs/
(for example: http://xxx.uni-augsburg.de/abs/astro-ph/0001024)
----------------------------------------
Astrophysics, abstract
astro-ph/0111600
From: Matthew J. Holman <mholman@cfa.harvard.edu>
Date: Fri, 30 Nov 2001 17:07:37 GMT (551kb)
Chaos in the Solar System
Authors: M. Lecar, F. Franklin, M. Holman, N. Murray
Comments: 65 pages, 27 figures
Journal-ref: Annual Review of Astronomy and Astrophysics, Vol. 39, p.
581-631 (2001)
The physical basis of chaos in the solar system is now better
understood: in all cases investigated so far, chaotic orbits
result from overlapping resonances. Perhaps the clearest examples
are found in the asteroid belt. Overlapping resonances account for
its Kirkwood gaps and were used to predict and find evidence for
very narrow gaps in the outer belt. Further afield, about one new
``short-period'' comet is discovered each year. They are believed
to come from the ``Kuiper Belt'' (at 40 AU or more) via chaotic
orbits produced by mean-motion and secular resonances with
Neptune. Finally, the planetary system itself is not immune from
chaos. In the inner solar system, overlapping secular resonances
have been identified as the possible source of chaos. For example,
Mercury, in 10^{12} years, may suffer a close encounter with Venus
or plunge into the Sun. In the outer solar system, three-body
resonances have been identified as a source of chaos, but on an
even longer time scale of 10^9 times the age of the solar system.
On the human time scale, the planets do follow their orbits in a
stately procession, and we can predict their trajectories for
hundreds of thousands of years. That is because the mavericks,
with shorter instability times, have long since been ejected. The
solar system is not stable; it is just old!
Paper: Source (551kb), PostScript, or Other formats
Astrophysics, abstract
astro-ph/0111602
From: Matthew J. Holman <mholman@cfa.harvard.edu>
Date (v1): Fri, 30 Nov 2001 17:36:07 GMT (150kb)
Date (revised v2): Sun, 2 Dec 2001 03:32:03 GMT (150kb)
The role of chaotic resonances in the solar system
Authors: N. Murray, M. Holman
Comments: 28 pages, 9 figures
Journal-ref: Nature, Volume 410, Issue 6830, pp. 773-779 (2001)
Our understanding of the Solar System has been revolutionized over
the past decade by the finding that the orbits of the planets are
inherently chaotic. In extreme cases, chaotic motions can change
the relative positions of the planets around stars, and even eject
a planet from a system. Moreover, the spin axis of a
planet-Earth's spin axis regulates our seasons-may evolve
chaotically, with adverse effects on the climates of otherwise
biologically interesting planets. Some of the recently discovered
extrasolar planetary systems contain multiple planets, and it is
likely that some of these are chaotic as well.
Paper: Source (150kb), PostScript, or Other formats
***************************************************************
Amara Graps | Max-Planck-Institut fuer Kernphysik
Interplanetary Dust Group | Saupfercheckweg 1
+49-6221-516-543 | 69117 Heidelberg, GERMANY
Amara.Graps@mpi-hd.mpg.de * http://galileo.mpi-hd.mpg.de/~graps
***************************************************************
"Never fight an inanimate object." - P. J. O'Rourke
This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 13:37:32 MST